Add some more metrics to the pooling allocator #11789
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This commit adds a few more metrics to the `PoolingAllocatorMetrics` type along the lines of accounting for more items as well as the unused slots in the pooling allocator. Notably the count of unused memory and table slots is exposed along with the number of bytes which are kept resident in these slots despite them not being in use. This involved a bit of plumbing to thread around the number of bytes that are actually kept resident to some more locations but is otherwise a pretty straightforward plumbing of accounting information we already had internally.
pchickey
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Oct 3, 2025
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| self.stripes | ||
| .iter() | ||
| .map(|i| i.allocator.unused_warm_slots()) | ||
| .sum() |
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I avoided this iteration + locking out of a (I guess probably irrational) fear of contention under heavy parallel load. Is that a pretty negligible concern here? If not, should we make a note about it in the pub method docs?
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I'll make a note yeah. My prediction is that it won't be too costly, but if it ends up causing problems we can probably work around it with atomic counters.
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This commit adds a few more metrics to the
PoolingAllocatorMetricstype along the lines of accounting for more items as well as the unused slots in the pooling allocator. Notably the count of unused memory and table slots is exposed along with the number of bytes which are kept resident in these slots despite them not being in use. This involved a bit of plumbing to thread around the number of bytes that are actually kept resident to some more locations but is otherwise a pretty straightforward plumbing of accounting information we already had internally.